Rework kcov kernel config. Instead of treating kcov as both an option and a

pseudo-device, get rid of the option. Enabling kcov now requires the following
line to be added to the kernel config:

  pseudo-device kcov 1

This is how pseudo devices are enabled in general. A side-effect of this change
is that dev/kcov.c will no longer be compiled by default.

Prodded by deraadt@; ok mpi@ visa@

9 files changed, 29 insertions, 42 deletions

diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index d3b593f71f4..dc1f1d4f6e9 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.458 2018/08/19 11:42:33 anton Exp $
+#	$OpenBSD: GENERIC,v 1.459 2018/08/21 18:06:12 anton Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -658,9 +658,6 @@ pseudo-device	hotplug		1	# devices hot plugging
 # mouse & keyboard multiplexor pseudo-devices
 pseudo-device	wsmux		2
 
-# kernel code coverage
-pseudo-device	kcov		1
-
 # Virtio devices
 virtio*		at pci?		# Virtio PCI device
 vioblk*		at virtio?	# Virtio block device
diff --git a/sys/arch/amd64/conf/Makefile.amd64 b/sys/arch/amd64/conf/Makefile.amd64
index e1ce1d7b410..bd1d63d12c5 100644
--- a/sys/arch/amd64/conf/Makefile.amd64
+++ b/sys/arch/amd64/conf/Makefile.amd64
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.amd64,v 1.100 2018/08/19 18:09:49 deraadt Exp $
+#	$OpenBSD: Makefile.amd64,v 1.101 2018/08/21 18:06:12 anton Exp $
 
 # For instructions on building kernels consult the config(8) and options(4)
 # manual pages.
@@ -43,10 +43,6 @@ SORTR=		cat
 .else
 CMACHFLAGS+=	-mretpoline
 .endif
-.if ${IDENT:M-DKCOV} && ${COMPILER_VERSION:Mclang}
-CMACHFLAGS+=	-fno-ret-protector
-PROF=		-fsanitize-coverage=trace-pc
-.endif
 .if ${COMPILER_VERSION:Mclang}
 NO_INTEGR_AS=	-no-integrated-as
 .endif
@@ -97,6 +93,11 @@ SYSTEM_LD_TAIL+=; umask 007; \
 LINKFLAGS+=	-S
 .endif
 
+.if ${SYSTEM_OBJ:Mkcov.o} && ${COMPILER_VERSION:Mclang}
+CMACHFLAGS+=	-fno-ret-protector
+PROF=		-fsanitize-coverage=trace-pc
+.endif
+
 %LOAD
 
 # cc's -MD puts the source and output paths in the dependency file;
@@ -139,7 +140,7 @@ vers.o: ${SYSTEM_DEP:Ngap.o}
 	sh $S/conf/newvers.sh
 	${CC} ${CFLAGS} ${CPPFLAGS} ${PROF} -c vers.c
 
-.if ${IDENT:M-DKCOV} && ${COMPILER_VERSION:Mclang}
+.if ${SYSTEM_OBJ:Mkcov.o} && ${COMPILER_VERSION:Mclang}
 kcov.o: $S/dev/kcov.c
 	${NORMAL_C} -fno-sanitize-coverage=trace-pc
 .endif
diff --git a/sys/arch/amd64/conf/files.amd64 b/sys/arch/amd64/conf/files.amd64
index b876aa897f4..fe34441c442 100644
--- a/sys/arch/amd64/conf/files.amd64
+++ b/sys/arch/amd64/conf/files.amd64
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.amd64,v 1.99 2018/08/19 18:01:05 deraadt Exp $
+#	$OpenBSD: files.amd64,v 1.100 2018/08/21 18:06:12 anton Exp $
 
 maxpartitions 16
 maxusers 2 16 128
@@ -245,12 +245,6 @@ file	arch/amd64/amd64/vmm.c			vmm		needs-flag
 file	arch/amd64/amd64/vmm_support.S		vmm
 
 #
-# KCOV
-#
-pseudo-device kcov
-file	dev/kcov.c				kcov		needs-flag
-
-#
 # Machine-independent SD/MMC drivers
 #
 include "dev/sdmmc/files.sdmmc"
diff --git a/sys/arch/i386/conf/GENERIC b/sys/arch/i386/conf/GENERIC
index 494d6e00d21..f1cb367391a 100644
--- a/sys/arch/i386/conf/GENERIC
+++ b/sys/arch/i386/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.834 2018/08/19 11:42:33 anton Exp $
+#	$OpenBSD: GENERIC,v 1.835 2018/08/21 18:06:12 anton Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -764,9 +764,6 @@ pseudo-device	hotplug		1	# devices hot plugging
 # mouse & keyboard multiplexor pseudo-devices
 pseudo-device	wsmux		2
 
-# kernel code coverage
-pseudo-device	kcov		1
-
 # Virtio devices
 virtio*		at pci? 	# Virtio PCI device
 vioblk*		at virtio?	# Virtio block device
diff --git a/sys/arch/i386/conf/Makefile.i386 b/sys/arch/i386/conf/Makefile.i386
index 7ca4991f1f6..18b7a98e80d 100644
--- a/sys/arch/i386/conf/Makefile.i386
+++ b/sys/arch/i386/conf/Makefile.i386
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.i386,v 1.125 2018/08/19 11:42:33 anton Exp $
+#	$OpenBSD: Makefile.i386,v 1.126 2018/08/21 18:06:12 anton Exp $
 
 # For instructions on building kernels consult the config(8) and options(4)
 # manual pages.
@@ -39,9 +39,6 @@ SORTR=		cat
 .else
 CMACHFLAGS+=	-mretpoline
 .endif
-.if ${IDENT:M-DKCOV} && ${COMPILER_VERSION:Mclang}
-PROF=		-fsanitize-coverage=trace-pc
-.endif
 .if ${COMPILER_VERSION:Mclang}
 NO_INTEGR_AS=	-no-integrated-as
 .endif
@@ -99,6 +96,10 @@ SYSTEM_LD_TAIL+=; umask 007; \
 LINKFLAGS+=	-S
 .endif
 
+.if ${SYSTEM_OBJ:Mkcov.o} && ${COMPILER_VERSION:Mclang}
+PROF=		-fsanitize-coverage=trace-pc
+.endif
+
 %LOAD
 
 # cc's -MD puts the source and output paths in the dependency file;
@@ -141,7 +142,7 @@ vers.o: ${SYSTEM_DEP:Ngap.o}
 	sh $S/conf/newvers.sh
 	${CC} ${CFLAGS} ${CPPFLAGS} ${PROF} -c vers.c
 
-.if ${IDENT:M-DKCOV} && ${COMPILER_VERSION:Mclang}
+.if ${SYSTEM_OBJ:Mkcov.o} && ${COMPILER_VERSION:Mclang}
 kcov.o: $S/dev/kcov.c
 	${NORMAL_C} -fno-sanitize-coverage=trace-pc
 .endif
diff --git a/sys/arch/i386/conf/files.i386 b/sys/arch/i386/conf/files.i386
index f70d8d3a6d2..ccc0b1206bc 100644
--- a/sys/arch/i386/conf/files.i386
+++ b/sys/arch/i386/conf/files.i386
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.i386,v 1.241 2018/08/19 18:01:05 deraadt Exp $
+#	$OpenBSD: files.i386,v 1.242 2018/08/21 18:06:12 anton Exp $
 #
 # new style config file for i386 architecture
 #
@@ -399,12 +399,6 @@ file	arch/i386/i386/vmm.c			vmm needs-flag
 file	arch/i386/i386/vmm_support.S		vmm
 
 #
-# KCOV
-#
-pseudo-device	kcov
-file		dev/kcov.c			kcov needs-flag
-
-#
 # IPMI
 #
 attach	ipmi at mainbus
diff --git a/sys/conf/files b/sys/conf/files
index e0b49cc8445..a196003bf54 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#	$OpenBSD: files,v 1.664 2018/07/13 09:25:22 beck Exp $
+#	$OpenBSD: files,v 1.665 2018/08/21 18:06:12 anton Exp $
 #	$NetBSD: files,v 1.87 1996/05/19 17:17:50 jonathan Exp $
 
 #	@(#)files.newconf	7.5 (Berkeley) 5/10/93
@@ -609,6 +609,9 @@ file	dev/hotplug.c			hotplug	needs-flag
 pseudo-device pppoe: ifnet, ether, sppp
 file 	net/if_pppoe.c			pppoe	needs-flag
 
+pseudo-device kcov
+file	dev/kcov.c			kcov	needs-flag
+
 # XXX machine-independent SCSI files should live somewhere here, maybe
 
 # kernel sources
diff --git a/sys/dev/kcov.c b/sys/dev/kcov.c
index cc8686a7927..1406969438d 100644
--- a/sys/dev/kcov.c
+++ b/sys/dev/kcov.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kcov.c,v 1.1 2018/08/19 11:42:33 anton Exp $	*/
+/*	$OpenBSD: kcov.c,v 1.2 2018/08/21 18:06:12 anton Exp $	*/
 
 /*
  * Copyright (c) 2018 Anton Lindqvist <anton@openbsd.org>
@@ -108,7 +108,6 @@ kcovattach(int count)
 int
 kcovopen(dev_t dev, int flag, int mode, struct proc *p)
 {
-#ifdef KCOV
 	struct kd *kd;
 
 	if (kd_lookup(minor(dev)) != NULL)
@@ -120,9 +119,6 @@ kcovopen(dev_t dev, int flag, int mode, struct proc *p)
 	kd->kd_unit = minor(dev);
 	TAILQ_INSERT_TAIL(&kd_list, kd, kd_entry);
 	return (0);
-#else
-	return (ENXIO);
-#endif
 }
 
 int
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 4bacf19e3de..0fff6edee2d 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exit.c,v 1.167 2018/08/19 11:42:33 anton Exp $	*/
+/*	$OpenBSD: kern_exit.c,v 1.168 2018/08/21 18:06:12 anton Exp $	*/
 /*	$NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $	*/
 
 /*
@@ -56,7 +56,6 @@
 #include <sys/filedesc.h>
 #include <sys/signalvar.h>
 #include <sys/sched.h>
-#include <sys/kcov.h>
 #include <sys/ktrace.h>
 #include <sys/pool.h>
 #include <sys/mutex.h>
@@ -71,6 +70,11 @@
 
 #include <uvm/uvm_extern.h>
 
+#include "kcov.h"
+#if NKCOV > 0
+#include <sys/kcov.h>
+#endif
+
 void	proc_finish_wait(struct proc *, struct proc *);
 void	process_zap(struct process *);
 void	proc_free(struct proc *);
@@ -190,7 +194,7 @@ exit1(struct proc *p, int rv, int flags)
 		acct_process(p);
 #endif
 
-#ifdef KCOV
+#if NKCOV > 0
 		kcov_exit(p);
 #endif